The Common Moorhen (Gallinula chloropus) (also known as the "swamp chicken"[2]) is a bird in the Rallidae family with an almost worldwide distribution. The North and South American Committees of the American Ornithologists' Union and the International Ornithological Committee have voted on or before July 2011 to split the American forms into a new species Common Gallinule, and implemented that decision;[3] however, no other committee has voted to change taxonomy yet.

The Common Moorhen lives around well-vegetated marshes, ponds, canals and other wetlands. The species is not found in the polar regions, or many tropical rainforests. Elsewhere it is likely the most common rail species, except for the Eurasian Coot or American Coot in some regions.